The human kidney is made up about 1 million nephrons, the working unit of the kidney. Each nephron is a very complex structure with highly specialized segments responsible for specific physiological functions. While the initial induction events of nephrogenesis have been well studied, the developmental patterning events that form the segments of the mature nephron are not well understood. The goal of this work is to understand the formation of the nephron by identifying transcriptional regulators involved in this process. To isolate segments of the nephron, we will use Auto-Fluorescent Protein reporters expressed in each segment of the nephron in transgenic mice. Using various expression profile techniques, we will compare each segment to identify genes differentially expressed in the nephron. Using a high throughput in situ hybridization approach we will characterize the expression of identified candidates in greater detail.